Solar Interior Rotation and its Variation

TL;DR

This paper reviews four decades of observational and helioseismic research on the Sun's internal rotation, detailing its structure, variations, and the relationship with models, highlighting advances in understanding solar dynamics.

Contribution

It provides a comprehensive survey of the development of observational knowledge on solar interior rotation and its temporal variations over forty years.

Findings

Detailed internal rotation profile of the Sun

Identification of the tachocline shear layer

Observation of temporal variations in rotation patterns

Abstract

This article surveys the development of observational understanding of the interior rotation of the Sun and its temporal variation over approximately forty years, starting with the 1960s attempts to determine the solar core rotation from oblateness and proceeding through the development of helioseismology to the detailed modern picture of the internal rotation deduced from continuous helioseismic observations during solar cycle 23. After introducing some basic helioseismic concepts, it covers, in turn, the rotation of the core and radiative interior, the "tachocline" shear layer at the base of the convection zone, the differential rotation in the convection zone, the near-surface shear, the pattern of migrating zonal flows known as the torsional oscillation, and the possible temporal variations at the bottom of the convection zone. For each area, the article also briefly explores the relationship between observations and models.